Apparatus for recording sounds.



T. A. EDISON. APPARATUS POR RECORDING SOUNDS,

APPLICATION FILED Nov.'13,'1903.

. Patented June 21, 1910.

2 SHEETS-SHEET l.

Attorney T. A. EDISON. APPARATUS fon RECORDING SOUNDS.

APPLICATION FILED NOV. 13, 1903.

Patented June 21.1910.

2 SHEETS-SHEET 2.

GNN

A tmmevv Witnesses resentative as may iunririi)y STATES PATENT OFFICE.

NEW JERSEY.

, THOMAS A. EDISON, OP LLEWELLYN PARK, ORANGE, NEW JERSEY;l AssIeNon ToNEw JERSEY PATENT COMPANY, Or ORANGE, NEW JERSEY, A CORPORATION Oia-APPARATUS POE RECORDING SOUNDS.

Speeication of Letters Patent. o Patented J nn 21, 1910.

ApplhiatioliVK filed November 13, 1903. Serial No. 180,998.1

To all whmri t may concern:

Be it known that I, THOMAS ALVA EDISON of Llewellyn Park, Orange, in thecounty of Essex and State of New Jersey, have inventedcertain-Improvements in Apparatus for Recordingr Sounds,- of which thefollowingisa description.`

My invention relates to limprovements in a paratus-for recording sounds,particularly oithat'type in which phonographic records'. are formed, andwhich records are of varyingl depth, but the invention ma be employed inconnectionV with recor s o f the amo hone type, which are of uniform pthut of irregular conformation The .object of this invention is to producea recording mechanism capable of recording sound wavesphoiioriaphically, as truly replbe of the original waves and theirquality, eliminating excessive and false amplitudes of vibration,without any consequent loss in volume of the sound produced.

The invention consists in the production of a phonographic devicewhereby sound waves throughout the range of music may be recorded andreproduced truly, false amplitudes of vibration of the recordingmechanism being eliminated, aiid the recording and reproduction of bothgrave fundamental notes and overtones rendered possible.

The invention further consists in the various details of constructionfor the improvenient of phonographic recorders generally, as more fullyset forth hereafter in the specifcation and the appended'claims.

At the present time those skilled in the art' have beenunable to recordand reproduce music having all the tones within the range of musicsuiciently like the original to obtain aA record: that is salableycommercially; this is especially'true of music of the piano, and,notwithstanding many millions of honograph records have been made andsolrecords formed of iano music alone are not sold and are not ound in anycatalogue of the manufacturers. With recording instruments existingbefore this invention, it is impossible to produce a satisfactoi-'ypiano record. If-.it is attempted to record the overtones which givemusic its pleasing qualities, the instrument must be made verysensitive, as the waves which form overtones are manyv times weaker thanthe f undamentals. If the recorder is made suhciently sensitive to sorecord'these overtones, the powerful fundamental tones of the bass :ictsoviolently upon the recorder as to throw the recording knife out of therecording material in the case of cylindrical records and give excessiveamplitudes in the case of fiat records. If the recorder is made soinsensitive as to prevent this latter action no overtones are recordedand the quality is lost. \Vliile at' the present time manufacturers ofcylindrical records use the piano as an accompaniment, the deep bassnotes are never used, but only those inthe higher register; in additionthe vibrating'part of the iecorder itself is sympathetic to the gravertones and serves only to intensify these serious defects. I have byexhaust-ive experimentation discovered that the true sound waves overthe whole range ofmusic from theinost grave to the highest pitched tonedo not actually have the amplitudes which are implied by the throwing ofthe recording knife out of contact with the record surface and thevibrating periods of the recorder itself need not necessarily be4graveythat this is due to defective mechanism con@ structed upon awrong principle and that if certain changes are made in the mechanism sothat it will operate upon a different principle, it may be adjusted withsutlicient sensitiveness to record the necessary overtones and the mostpowerful bass notes of a piano and permit the reproduction of theoriginal tone with almost perfect qualityand with a greater volume thanhas hitherto been thought possible. I have traced down and ascertainedby experiment that the cause of the excessive and false amplitudes ofvibration is due to the elasticity of the recording mechanism itself andby eliminating theV principal part of this elasticity, the trueamplitudes due;y to the sound waves do not cause the recording knife tobe thrown from the recording surface when the recorder is renderedsuiliciently sensitive and that the grave tones of the diaphragm may bechanged to a higher rate and O such a small amplitude as not to distorttherecord.

The Ordinary recording mechanism now in general use oonsists of acircular diaphragm generally of glass about 1&1,- inches inl connectedto a lever secured to the waves and the elastic rubber which islstrained by the flexing of the disk. For the purposes of illustrationlet 'such a disk be cut in sections like the spokesiof a wheel, therewill be a numberof vibrating reeds each elastic and flexing by itself aswell as flexing by distortion of its rubber support, and sympatheticallyresonant to some tone in the lower register of the iano, harp or similarinstrument. Indepen ent of the fact of its having a tone or vibratingperiod, it has a mass and possesses weight and if movl by a forceapplied at the end of such a section a large amount of the power appliedmust be lused in distorting the rubber clamp in addition to that use forexing the section, and this mass under the action of the stored power inthe rubber tends to make several movements when only a single impulsewas given to its end thus it cannot ossibly follow the sound waves ofmusic. f anumber of impulses are appliedvto the end which im ulses havethe same period of vibration as the section itself, the amplitude due tothe first few waves will be less than the following waves, althou h theoriginal sound waves may all have t e same amplitude, hence there can beno true record of a ltone the same as that of the sector, and this istrue of the whole diaphragm.which is formed of a large numberofvsections, so to s ak. It is impossible to make the rubber c amps ofuniform elasticity, hence there will e man parts or sections of thediahragm wi different vibrating eriods. lven in the case of waves havinv1 rating periods unlike the diaphragm, t eir action on the diaphragmcauses energy to be stored up in the elastic clamp, and the action ofthis stored energyon the mass of the dia- -iexing the ver elastic g asswoul increase the vo ume of sound, and permit of hragm tends to force itto make more virations than there are sound waves producing interferenceand false amplitu corresponding to the sound wavesand a lar e proportionof the ener contained in eac sound wave is lost as gevat in deformingth'e yrubber (which extends around the' periphery of a circle about 3%inches in circum erence), which ener if applied to greatly the recordingof the exceedin ly weak overtones. I may mention that t e heat. lost byiioats :liquid material. The diaphragm is secured lat its center to oneend of a reed which is es not` distorting rubber is very much greaterthan by distorting glass, as the latter is a substance of greatelasticit and minimum internal friction, while rubber is just thecontrary. The recorder in general use is also defective by reason ofcertain other causes which coperate to produce distortion of the diahragm. First, the diaphragm is placed un er strain by the pressurewhichis necessary to force the redording knife into the record material. onlywith the material but with different degrees of hardness occurring upondifferent parts of the surface of the record material.

econd, the record itself cannot be made to' run absolutely true. Thesetwo causes work in conjunction to ,produce an ever varyin lexure of thediaphragm, independent o the action of the sound waves', andthiscontinuous iie`xure of itself distorts the record roduced by. thesound waves. Third, the

act that, the fundamental tone of the diaphragm and its elastic supportis grave and of great amplitude, and constantly varies as the tone isprolonged, produces additional distortion.

In the recorder of my invention, a very `wide departure in constructionis made. The

diaphragm is not secured at theedges but 1n a mass of viscous liquid, orsemisupported at its other end by an elastic connection from thechamber, and has the recording knife fastened at its end about thecenter of the diaphragm. When assembled the diaphragm and knife areafloat so to speak, and are sustained entirely by the supported end ofthe reed. The viscosity of t e semi-liquid material around the edges issuch that when the recorder is adjusted so the knife tracks the recordmaterial to the proper depth, the diaphragm will have no stress upon it.It is in its `most sensitive condition, and if the record cvlinder iseccentric or a part ofthe record harder than another part,the viscousliquid olers scarcely any resistance to a motion of translation to suchslow movements but on the other hand acts Anearly as a rigid body tomovementsl of great uency similar to sound waves. The ,edge of thediaphragm makes scarcely vany movement and yet is free of all strainwhereas ifzthe record is untrue the edge of the diaphragml may makemovements several times greater than those produced by the sound waves.Thus no matter what variation in the hardness of the material or whatreasonable amount of eccentric motion of the record takesv place, thedia permits of a rise `and fal of barometric pressure which permitssound waves, and

phragmvis unstressed and in its most sensitive con- .'dition. Theviscous semi-liquid material acts' to close the ychamber completely andthus 'I5A v This pressure varies not lio lus

I' taken on the seapaiA being non-elastic no energy is stored uptodistort the sound Waves, and the amount'of energy abstracted is lessthan if the diaphragm were between rings of rubber or other elasticmaterial, and such energy is not returnable to the mechanism as motionto produce distortion. In addition', this want of elasticity 'changesthe fundamental note of the diaphra' i and` environment from a. graveiiote oglliigh amplitude to a very inucli liiglieriiote and of a greatlyreduced amplitude combined effect of vthe sound waveand the diaphragm intune with it is entirely insuiii- .cient to throw the knife from therecord or disturb in an appreciable amountthe quality of the recordersound. The viscosity of the material used around the edges is such thatitsl surface tension prevents it from flowing to any extent at ordinarytemperature at slight gravity gradients, hence the recording a paratusif kept level will be serviceable fbr semi-Huid material .is .quicklyand easily renewed.

Iii order that the invention may be better understood, attention isdirectedto the'accompanying drawings, forming a part of thisspecification, and in which Figure 1 is a bottom view of the recorder;Fig. 2 is a sectional view thereof line 2-2 of Fig. 1; Fig. 3 is asectional view taken on the -line 3-3 of Fig. 2; Fig. 4 is a front viewof the body; and Fig. 5 is an enlarged sectional view of the body,diaphragm and recording knife.

In `all of the above views corresponding parts are represented by thesame numerals of reference. y

The liollowed tube 1, which is connected to, or is a continuation of thevusual horn or funnel, is carried by the usual support (not shown) andhas ears 2-2 between which is pivoted the head or barrel 3. To tli'elatter is secured the sound box or body 4 to the lowerA face of which'isconnected f the glass or mica diaphragm 5. Across the lower face of thebody and below thev diaphragrn is the tracking lever 6, which serves asa support for 'theball 7, which latter rests upon the record kcylinderand supports the body, allowing it to oscillate about the pivot betweenthe ears 2 2 and accominodate itself to all large irregularities in thesurface of the blank. i

The `ball 7 is of a comparatively little curvature, but sufficient topermit of universal adjustment, Aand is preferably made of a jewel, ofwhich sapphire seems to be the best material, as it does not have anyappreciable chemical effect-upon the record blaiik;. furthermore it issusceptible of taking a high polish, so that its passage over the recordwill not scratch or otherwise injure it.

so much reduced that thev several days and then the viscous` body 4 bymeans of a screw 8, which passes through a. slot 9 formed within anelastic extension 10 of the lever which forms an elasticl connection,'sothat the lever, too'ether extremity of the lever engages with anladjusting screw 11, passing through a threaded opening in an extension12 on the body, and

the ball 7 and the body may be adjusted whenthe machine is running.

The knife 13 is attached to the diaphragm adjacentl to its center andonthe saine luie magnesium on account of lightness.y The 4foot 14issecured to the diaphra by a suitable cement, such as melted lshel ac.

The diaphragm is connected at its-periphery to the bottom of the chamberor body by means of a mass of viscous or semiliquid material 15,50 thatit 'will be entirely supported agiainst gravit yand the thrust of thecutting nife solely by the elastic reed 1,6, the material 15 forming a'seal to close the joint between the edges ofthe diaphra in and thechamber. The reedis preferaly made of white pine or similar light woodand is of a varying vertical section, deeper than it is wide and issecured to the foot 14 by a cement, referabl melted shellac.

The end of) the ree at 17 is made much thinner, so that it will vibrate,easily and the sions, toward t e fixed extremity, the` configuration ofthe entire reed bei such that it will be practically unsympat etic withany note of great amplitude, and on account of the varying verticalsection will give no harmonics that would tend to disturb the record.The end 17 of the reed is secured the body 4. l n

The stiffness of the reed at 17 should be suficient, so that the act oftracking the kniferin'the record will not cause the edlge of thediaphrgm to be forced lagainst t e edge `of the b y 4, .but onl moved inthe viscous'liquid. The knife ilustrated is of yusual form. The reed 16'forms a continuathrust caused by the action of the record upon theknife. When the reed is arranged at an angle to the thrust/caused by theaction of the record on the knife, the knife has a i tendency torchatter which injuriously affects the record. v

The mass of viscous or semi-fluid material 15 does not serve to supportthe diaphragm f' against gravity, but serves as a moving point or pointsabout which the dia hragm vibrates. It is necessary to keep t equantityof viscous material in use in the manner The 'lever 6 is connected toone-end of the with the ball 7 may be adjusted in relation to the centerof the diaphragm. The other,

by means of which 'the relative position of to a pillar 18 formed upon acontinuation` of of travelas the ball 7, by means of a su port or foot14 which is formed preferab y of j reed increases radually in verticaldimention of the knife,and is in the direct line of shown, down to thesmallest guantit mit of its surface tension being s cient; to

hold it u in position, and not flow to any tension and fgreat viscosity,it is not chan ed encircling flan conditions.`

- `ticall continuous with the upper surface by action o the atmosphereand altoget er is a peculiar substance and well adapted for the purpose.It'can be produced of varying degrees of viscosity by a propermanipula,- tion of the heat and thus give a range for varyin conditions.The space between the inner e' ge of the diaphragm and thebody 4 willusually be .020 of an inch and between the of the diaphragm and theinside 19 about .010 of an inch and below the ower edge and the iiange19 shoul project a suicient distance to hold the viscous material. Thesedimensions can be varied to meet varying The form of recorder which Inave devised and which is illustrated in Figs. 1 and 2 also has someadvantages over that in common use, as the chamberfor producing the nalpressures upon the diaphragm is small and of a roper pro rtion and is soarranged in ation to t e receiving nel or horn that the sound waves donot suf.-

fer either partial or total deflection at anyl int and aty the same timethe wall friction is reduced. This is acco f lished by forming the heador barrel 3 o the same width practically throughout (see Fig.` 1 and nottaperin it as it aterally enters t e body 4 as has Vtherto been thepractice. The telp o t e o -within the headv 3 a proac as theynil'ntlhge diaphragm, but tbl; sides do not. The top 20 of the headforms a line prac- 22 o the inside of the body 4, which upper surfaceinclines from a with the connection of the ead, to the other edge of thediaphragm at 23; and there are no angles or obstructions inthe th of thesound waves. B connect' e head 3 with ythe sideof e body 4, A e airpassage way 'is straight, consequently the `sound waves do not suer anydeiiection and by the use of the proper funnel angle the power of thesound waves to act upon the ,diaphragm is greatly increased.

A small weight 24 is preferabl remove ably carried on the head 4,'and wichmay be changed or varied to suit the conditions of .work, orcharacter of sound required.

The center of gravity ofthe weight shouldr t0 per:

mit of the adjustment of tracking of the diaphragm oeaos'i ordinari] bedirectly over the center of the trackin all 7. v

` By a justing the position of the ball 7 upon therecord by means of thescrew 11, the whole recorder canv rapidly and easily be made to approachand recede from the face of the recording material and thus perof therecording knife to the required depth into the record material after themachine is started. In theactof forcing the knife into the recordmaterial, the reed 16 is flexed at its point of fastening 17. If thereduced section ofthe reed at 17 is made stiff the reed as a whole willbe very little flexed and there will be but a slight movement of theedge of the diaphragm in the viscous semi-liquid material, and uring theact of flexing of the reed, the diaphragm will also be exed due to theretardation of its movement through theY viscous li uid, but when theknife :is once tracked a stress on the diaphragm is removed.` To rapidmovements, ike sound waves, the resistance to motion is powerful and thediaphragm has little, if any, to'and fro movementl at its edges, therecording bein due almost entirely to flexing of the'diap ragm. l

If the part 17 of the reed is made very thin, the reed will be fiexed toa eater extent and the movement of the diap agm in the viscous liquidwill be eater, but in no case will the edge of t e diaphragm touch themetallic parts, but will always be and immersed in the li uid. Amovement `of more than .02 o an inch will seldom be required and theproportions illustrated should be suiiicient to permitv of movements ofthis amount. The thickness of th reed at 17 is easily changed, andserves to adjust the sensitiveness of the whole vibrating portion of therecorder and the ener stored up in the elasticity of that portion of thereed at 17 is quite small as comared to that of a diaphragm clamped inrub rs -atits edges, hence the movements of the vibrating apparatusdueto its own elasticity or capacity to returnthe stored up energy is verysmall and negli 'ble and thereforevthe full effect of the con ensatioiisand rarecations ofthe sound waves comes into full playwithout thedisturbance produced by elastic mechanism4 of the recorder mechanism asnow used. v

It is obvious that the principle of operation can be varied in many waysand that it can be employed for recording on machines of the disk forni,to prevent the making of a record of excessive amplitudes, produced' bythe conjunction of the sound waves and elastic recording mechanism andwhich the reroducin needle does not and cannot folow, but Jumps across,and also to recordthe sound more perfectl tones and increase e volume ofsound..

, to strengthen the over- While I have described my improvements asbeing particularly designed for .use in a aparatus of the phonographtype, it will bev I which flow more or lessj'readily, some of which aresometimes termed semi-liquid materials, the consistency of the materialbeing only determined by ,the qualification that it must be-characterized by great internal friction or viscosity.

y Having now described my invention, what I claim as new and-desire tosecure by Letters Patent, is as follows:

1. In a device for recordingsound waves, a. vibratory plateory diskconnected to a frame by a permanently liquid material which ischaracterized by reat internal friction or viscosity, substantially asset forth.

2. vIn a device for recording sound waves, a vibratory plate or diskconnected to a frame by burnt rubber, substantially as set forth.

3. In a device yforfrecording sound Waves, a vibi-atory plate or disk,the edges of which are connected to a frame by a permanently liquidmaterial which is characterized by great internal friction or viscosity,substan- Y liquid material characterized by great intiallyy as setforth. 4 t

4. In a device for recording sound waves, a vibratory plate or disksupported at or near its center and connected to a frame by apermanently liquid material which is characterized by great internalfriction or visy cosityfsubstantiallyas set forth.

5. In a device for recording sound waves, a vibratory plate or disksupported at or near its center and connected to a yframe by burntrubber, substantially as set forth.

6. In a device for recording sound Waves, the combination of a vrecordsurface, a diaphragm and stylus capable of moving as a phragm and at itsother end t'o a whole toward and away from said surface and a reedconnected` atone end to the diaphragm and at its other end to a supportand operating. to support they diaphragm and. by1 flexure to permitmovements of the diap ragm, substantially as set forth.

7. In a device for recording sound Waves, the combination of a recordsurface, a diaphragm and stylus capable of moving as a whole toward andaway ,from said sur ce, `a reed connected at or near one end to thediasupport and operating to support the diaphra m and by iexure topermit movements of tie diara said reed extending longitudinally ih linewith the thrust of the record sur-'p` face upon 'the recording stylus,substantially y as set forth. I

8. In a. device for recording sound waves, the combination of asound oxhavingan opening, a diaphragm occupying a position. 4 within saidopening and a seal between said diaphragm and opening composed of aypermanently liquid material .characterized Vby great internal frictionor viscosity, substantially as set forth. r

9. In a device for recordin soundl waves, the combination of a sound ox'having an opening, a 4diaphragm occupying a position within said openingand a seal between said dia hragm and opening com osed of burnt rub er,substantial 1y as setl orth.

10. In a devicefoiirecording sound waves, the combination of a soundboxfhaving an opening, a diaphra ni Within said opening, a supportconnected to said diaphragm at or near its center and a seal betweensaid diaphragm'and' opening composed of a permanently l'liquid materialhaving great internal friction or viscosity, substantially as Asetforth.

11. In a device for recording sound waves, the combination of a soundbox having an opening, a diaphragm within said opening, asupportjconnected to said diaphragm at or near its center and a sealbetween said diaphragm vand opening composed of burnt rubber,substantially as set forth.

12. In a device for` recording sound waves, f

the combination of a vibratory diaphragm connected to a frame by apermanently ternal friction or viscosity, and a reed connected at oneend to the diaphragm and at its other end to a support, and operating byflexure to ermit movements of the diaphragm, su stantially as setyforth.

'13. In a device for recording sound waves, the combination of avibratory diaphragm connected at or near its edges to a frame by apermanently liquid material, characterized byV great internal frictionor viscosity, and

connected at or near its center to a vibratory support, substantially asset forth.

14. In a device for recordingsoundv Waves, the combination of avibratory diaphragm connected at or near its edges to a frame y burntrubber, and connected at or near its center to a vibratory support,substantially as set forth.

16. In a device for recording sound waves,'

whole toward and away .tlexure to the combinatlon of a record surface, adiaphragn'i and stylus capable of moving as a from said surface, and awooden reed connected at one'end to the diaphragm and at the other endto a support and operating to support the diaphragm and by fiexure topermit movement of the diaphragm and stylus, substantially as set forth.

17. Inga device for recording sound waves, the combination of a recordsurface, a diaphragm and stylus capable of moving as a whole toward andaway from said surface, and a reed connected at one end to the diaphragmand having its other end of reduced section and connected to a sup ort,said reed operating to support the diap ragm and by llexnre to permitmoif'ement o -the dia'- phragni and stylus, substantially as set forth.1S. In a device for recording sound waves, the combination of a recordsurface, a diaphragm, a stylus moving toward and away from said surfaceand a reed of tapered vertical section connected to said dia hragm, andhaving its other end of reduce section and connected to a support andoperating by ermit movements 'of the diaphragm andpstylim,l the largestvertical section of the reed being adjacent the reduced portion,substantially as set forth. 1 l

19. In a devicelfor recording sound waves, the combination `of a soundbox havingv an opening closed by a dia hragm and a second opening forreceiving t e sound waves, said latter opening being substantially equalin width to the diaphragm opening, substantially as set forth.

20. In a device for recordin sound waves, the combination of a sound oxhaving an opening closed by a dia hragm and a second opening forreceiving t e sound waves, said latter opening being substantially equalin width to the diaphragm opening and situ- [sean] ingbeingsubstantially equal in opening to a point adjacent the far ed ated atone side thereof, substantially as l forth.

21. In a device forrecordin the combination of a sound opening closed bya diaphra and a second opening communicating wi a ssage for conveylngthe sound waves, said atter openwidth to the diaphragm o eningfandsituated at one side thereof, and t e lateral walls of the said passagebeing arallel, substantially asset forth.

22. In a evice for recording sound waves,

sound waves, `x having an a sound box having an opening in which thediaphragm is situated, a wall opposite said opening, anda second openinat one side of the diaphragm opening, sai walls slopi uniformly from apoint adjacent the secoii` o the diaphragm, substantially as set for 23.In a device for recordln sound waves, the combination of a sound openingin which the diaphragm is situated and a sound conveyin tube openinginto the side of saidkbox e upper and lower walls of said tube an soundbox converging as they approach the diaphragm, substantially as setforth'.

24. In a device for 'recordi the combination of a soundl opening inwhich the dia and a sound conveying tu opening into the side of saidbox, the upper and lower walls of said tube and sound box converging asthey approach the diaphragm and the top of the sound box beingractically a continuation of the u per wail of the tube, substantiallyas set fbrth. v

x having an hragm -is situated ox having an 70 sound waves,

'lis

This specification sigiedand witnessed this 11th day yof Novem r 1903. y

THOMAS A. EDISON. Witnesses: f

LEONARD A. Dran, JN0. Roar. Tanon.

'n n hereby Certified ,that in Letters Patent No. 962,081, grand'June21,1910,` upon the application of Thomas A. Edison, of Llewellyn Park,Grange, New Jersey, foran improvement in Apparatus for Recording Sounds,errors appear in the y printed specification requiringcorreetion, asfollows: Page 4, line '42, the word laterally should be stricken out andinserted after the word fit,"samealine, first. occurrence, and samepage, line 116 the word raretcations should read 'm1-efectivas; and thatthe said 'Letters Patent should be read with these corrections thereinthat the same may conform to the record of thecase inthe Patent Oce.

signed und sealed his 20th day of september, A. n., 1910.

C. C. BILLINGS, Acting Commissioner of Patente.

whole toward and away .tlexure to the combinatlon of a record surface, adiaphragn'i and stylus capable of moving as a from said surface, and awooden reed connected at one'end to the diaphragm and at the other endto a support and operating to support the diaphragm and by fiexure topermit movement of the diaphragm and stylus, substantially as set forth.

17. Inga device for recording sound waves, the combination of a recordsurface, a diaphragm and stylus capable of moving as a whole toward andaway from said surface, and a reed connected at one end to the diaphragmand having its other end of reduced section and connected to a sup ort,said reed operating to support the diap ragm and by llexnre to permitmoif'ement o -the dia'- phragni and stylus, substantially as set forth.1S. In a device for recording sound waves, the combination of a recordsurface, a diaphragm, a stylus moving toward and away from said surfaceand a reed of tapered vertical section connected to said dia hra andhaving its other end of reduce section and connected to a support andoperating by ermit movements 'of the diaphragm andpstylim,l the largestvertical section of the reed being adjacent the reduced portion,substantially as set forth. 1 l

19. In a devicelfor recording sound waves, the combination `of a soundbox havingv an opening closed by a dia hragm and a second opening forreceiving t e sound waves, said latter opening being substantially equalin width to the diaphragm opening, substantially as set forth.

20. In a device for recordin sound waves, the combination of a sound oxhaving an opening closed by a dia hragm and a second opening forreceiving t e sound waves, said latter opening being substantially equalin width to the diaphragm opening and situ- [sean] ingbeingsubstantially equal in opening to a point adjacent the far ed ated atone side thereof, substantially as l forth.

21. In a device forrecordin the combination of a sound opening closed bya diaphra and a second opening communicating wi a ssage for conveylngthe sound waves, said atter openwidth to the diaphragm o eningfandsituated at one side thereof, and t e lateral walls of the said passagebeing arallel, substantially asset forth.

22. In a evice for recording sound waves,

sound waves, `x having an a sound box having an opening in which thediaphragm is situated, a wall opposite said opening, anda second openinat one side of the diaphragm opening, sai walls slopi uniformly from apoint adjacent the secoii` o the diaphragm, substantially as set for 23.In a device for recordln sound waves, the combination of a sound openingin which the diaphragm is situated and a sound conveyin tube openinginto the side of saidkbox e upper and lower walls of said tube an soundbox converging as they approach the diaphragm, substantially as setforth'.

24. In a device for 'recordi the combination of a soundl opening inwhich the dia and a sound conveying tu opening into the side of saidbox, the upper and lower walls of said tube and sound box converging asthey approach the diaphragm and the top of the sound box beingractically a continuation of the u per wail of the tube, substantiallyas set fbrth. r v

This specification si edand witnessed this 11th day yof N ovemiir 1903.y

- THOMAS A. EDISON. Witnesses: f

LEONARD A. Dran, JN0. Roar. Tanon.

x having an hragm -is situated 'n n hereby Certified ,that in LettersPatent No. 962,081, grand'June 21,1910,` upon the application of ThomasA. Edison, of Llewellyn Park, Grange, New Jersey, foran improvement inApparatus for Recording Sounds, errors appear in the y printedspecification requiringcorreetion, as follows: Page 4, line '42, theword laterally should be stricken out and inserted after the wordfit,"samealine, first. occurrence, and same page, line 116 the wordraretcations should read 'm1-efectivas; and that the said 'LettersPatent should be read with these corrections therein that the same mayconform to the record of thecase inthe Patent Oce.

signed und sealed his 20th day of september, A. n., 1910.

C. C. BILLINGS, Acting Commissioner of Patente.

ox having an sound waves,

'lis

Corrections in Letters Patent No. 962,081.

lt is hereby certified that in Letters Patent No. 962,081, granted June21, 1910,

upon the application of Thomas A. Edison, of Llewellyn Park, Orange, NewJersey, l for nn improvement in Apparatus for Recording Sounds, errorsappear vin the l printed speeicntion requiring correction, as follows:Page 4, line 42, the word ,i laterally should be stricken out andinserted after the word Mit,V

i 5 first occurrence, and same page, line 116 the word rarecationsshould read same line,

rmwfac/z'nns; and that the said 'Letters Patent should be read withthese oorretions i therein that the same may conform to the record ofthe casein the Patent Oiee.

Signed und sealed this 20th day of September, A. D., 1910.

C. C. BILLINGS,

Acting Gommssomr QfPafenta.

[SEAL] l

